Lithium based batteries are used in a variety of applications, such as videotape recorders, communications devices and many portable devices. Generally, the lithium battery industry has employed LiCoO2-type material as the active component of lithium battery cathodes. However, LiCoO2 lithium battery cathodes are typically expensive. Moreover, lithium-containing transition metal oxides such as LiCoO2 suffer a problem that they have low thermal stability in the charged state when in contact with an organic electrolyte. Since LiCoO2 consists of platy particles, the particles tend to show high orientation, and in case where there is high or increased bulk density, the LiCoO2 particles become oriented in parallel with the collector. This leads not only in a decrease in the penetration of the electrolyte but also in hindrance in maintaining the presence of crystallographic planes through which occlusion and discharge of lithium ions takes place. Accordingly, LiCoO2 had problems of decreasing capacity characteristics such as high rate discharge properties in case of increasing bulk density of the electrode.
LiCoO2 expands on charging and contract on discharging or deintercalating. However, other lithium-containing transition metal oxides with a spinel type structure contract on charging and expand on deintercalating. By using a mixture of these transition metal oxides there is an improvement in thermal stability and capacity.
Currently, the preferred way to make LiCoO2 is by running the following reaction up to 900° C. in two steps:Li2CO3+⅔Co3O4→2LiCoO2+CO2 
The lithium carbonate sinters badly at about 500-600° C. and the sintered partially reacted mixture is ground at this point. The mixture is again placed back in the furnace and then heated to 900° C. for six or more hours. The powder is again milled, screened and then packaged. This process is labor intensive, slow and expensive.
U.S. Pat. No. 6,790,560 to Wakihara, which is herein incorporated by reference, discloses a lithium manganese oxide that has a spinel structure having a metallic element other than Li and Mn which is Ni, Al, Cr or Mg that is prepared with three heating steps including under controlled oxygen, partial pressure and quenching.
U.S. Pat. No. 6,818,315 to Sernagawa et al which is herein incorporated by reference, discloses the preparation of a cathode which can be used with the present invention. However, the cathode active components are a mixture of LiCoO2 and spinel type lithium manganate.
U.S. Pat. No. 6,872,491 to Kanai et al, which is herein incorporated by reference, discloses the preparation of cathodes for lithium ion secondary batteries. There is disclosed that lithium batteries using lithium manganese composite oxide are unstable at high temperatures. Also, the crystal structure of LiNiO2 is unstable at higher temperatures. There is also disclosed a process of preparing cathodes which can be used in the present invention.
U.S. Pat. No. 6,818,351 to Sernagawa et al which is herein incorporated by reference discloses the preparation of lithium secondary battery cathodes with spinel type lithium manganese oxide and lithium containing cobalt oxide.
U.S. Pat. No. 6,855,461 to Lampe-Onnerod which is herein incorporated by reference, discloses the preparation of lithium battery cathodes with lithium oxide compositions containing an element selected from aluminum, gallium, magnesium, vanadium, titanium and zirconium.